content是UILabel（contentLabel）的字符串内容，contentLabel是UILabel

    NSMutableAttributedString *attStr = [[NSMutableAttributedString alloc]initWithString:content];
    
    NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc]init];
    [style setLineSpacing:5.0f];
    CGFloat textWidth = self.contentLabel.bounds.size.width;
    NSInteger leng = textWidth;
    if (attStr.length < textWidth) {
        leng = attStr.length;
    }
    [attStr addAttribute:NSParagraphStyleAttributeName value:style range:NSMakeRange(0, leng)];
    //Label获取attStr式样
    self.contentLabel.attributedText = attStr;
    [self.contentLabel sizeToFit];